title: Evaluation design for community-based physical activity programs for socially disadvantaged groups: communities on the move.
abstract: BACKGROUND
  As interventions are not yet successful in substantially improving physical activity levels of low socioeconomic status groups in the Netherlands, it is a challenge to undertake more effective interventions. Participatory community-based physical activity interventions such as Communities on the Move (CoM) seem promising. Evaluating their effectiveness, however, calls for appropriate evaluation approaches.
  
  
  OBJECTIVE
  This paper provides the conceptual model for the development of a context-sensitive monitoring and evaluation approach in order to (1) measure the effectiveness and cost-effectiveness of CoM, and (2) develop an evaluation design enabling the identification of underlying mechanisms which explain what works and why in community-based physical activity programs.
  
  
  METHODS
  A cohort design is proposed, based on multiple cases, measuring impact, processes, and changes at each of the distinguished levels. The methods described in this paper will evaluate both short- and long-term effects, costs, and benefits of CoM.
  
  
  RESULTS
  Testing of the proposed model began in October 2012 and is on-going.
  
  
  CONCLUSIONS
  The design offers a valid research strategy for evaluating the effectiveness of community-based physical activity programs. Internal validity is guaranteed by the use of several verification techniques such as triangulation. The multiple case studies at the program and community levels enhance external validity.
authors.affiliation: Chairgroup Health and Society, Department of Social Sciences, Wageningen University and Research Centre, Wageningen, Netherlands. marion.herens@wur.nl.
authors.forename: Marion
authors.initials: M
authors.lastname: Herens
authors.forename: Annemarie
authors.initials: A
authors.lastname: Wagemakers
authors.forename: Lenneke
authors.initials: L
authors.lastname: Vaandrager
authors.forename: Johan
authors.initials: J
authors.lastname: Van Ophem
authors.forename: Maria
authors.initials: M
authors.lastname: Koelen
keywords: community-based physical activity program; cost-effectiveness; evaluation design; health promotion; low socioeconomic status groups